Home      Services      Sub Surface Investigation

It is our opinion that this proven technology is the way forward for locating oil leaks in:
Underground High Voltage Oil Filled Cables.

Applications include, the location of underground:-
  • Water, Gas & Steam Leaks

  • Oil Filled Cable Leaks

  • Oil Pipeline Leaks

  • Location of Utility Services

  • Location of Sub-Surface Unknowns.

Water Tech UK

Researched many of the systems available, established each ones individual assets, found the best among them and now provides an unrivalled service.

Ground penetrating radar is a non-destructive geophysical method that produces a continuous cross-sectional profile or record of subsurface features, without drilling, probing, or digging.
Ground penetrating radar (GPR) profiles are used for evaluating the location and depth of objects and to investigate the presence and continuity of subsurface conditions and features.
Ground penetrating radar operates by transmitting pulses of ultra high frequency radio waves down into the ground through an antenna. Several antennae are available ranging in centre frequency from 25 to 1500 MHz. The selection of antennae is dependent on the soil conditions and depth of penetration.
When the transmitted signal enters the ground, it contacts objects or subsurface strata with different electrical conductivities and dielectric constants. Part of the ground penetrating radar waves reflects off the object or interface; while the rest of the waves pass through to the next interface.
The reflected signals return to the antenna, pass through the antenna, and are received by the digital control unit. Two-way travel time is used to calculate the reflector depth assuming that the velocity of the material being tested is reasonably estimated or known.
The control unit registers the reflections against two-way travel time in nanoseconds and then amplifies the signals. The output signal voltage peaks are plotted on the ground penetrating radar profile as different colour bands by the digital control unit.
For each reflected wave, the radar signal changes polarity twice. These polarity changes produce three bands on the radar profile for each interface contacted by the radar wave. This forms the basis of collating results.

This image was obtained during a survey to find oil leaking from a HV oil filled cable. The profile clearly depicts two trenches and a cable joint bay.
All profiles obtained for lines 43 to 49 clearly show cable location, a gas main is depicted by the large reflector close to the surface (shallower in depth).

The location of two additional services (electric cables) deeper than the gas main can be seen in the profile below.

  • The incoming data signals show the interface between all the materials the radio signal has passed through prior to it’s return to the equipment.

In one investigation, we will provide you with all of the sub-surface information you require to solve your problem